# Effects of genotype × environment interactions on the morphological and genetic aspects of the seed characteristics of faba beans

## TL;DR

This study explores how faba bean seed traits vary with environment and genotype, identifying two high-performing genotypes and genetic markers linked to seed characteristics.

## Contribution

The study identifies genotype × environment interactions and discovers novel SNPs associated with multiple seed traits in faba beans.

## Key findings

- Genotype × environment interactions significantly affect seed characteristics in faba beans.
- FB-227 and FB-231 showed stable performance across locations with high values for seed characteristics.
- Several SNPs were found to be associated with multiple seed traits, offering potential for marker-assisted breeding.

## Abstract

Faba bean (Vicia faba L.) is one of the oldest cultivated crops in the world. It is the third most important feed grain legume globally, after soybean and lupin. It is an autogamous plant with a partial outcrossing rate ranging from 20% to 80%. The objective of most faba bean improvement programs is to enhance yield; however, yield is a complex trait influenced by many other traits. Therefore, in this study, we focused on seed traits that are related to faba bean yield. A set of 110 faba bean genotypes was tested across two different locations (Germany and Egypt) to investigate the effect of genotype–environment interactions and identify single‐nucleotide polymorphism (SNPs) related to seed characteristics. This study revealed that there is high genetic variation among genotypes in all traits in each location, and the genotype × location interactions were significant. There was a strong positive correlation among the seed characteristics within each location, but the correlations between the two locations were weak or not significant. FB‐231 and FB‐227 performed very well in both countries based on the selection index (SI) values, whereas FB‐193 and FB‐185 had the lowest SI values in both countries. All genotypes were genotyped via single primer enrichment technology, which resulted in 33,165 SNP markers. The association mapping revealed 162 and 31 significant SNPs in seed traits scored in Germany and Egypt, respectively. A set of seven SNPs was associated with more than one seed trait in Germany, whereas only one SNP was associated with two traits in Egypt. No shared markers were found between the two locations for any of the seed traits. These markers represent potential targets for future breeding programs to enhance seed size and understanding of its genetic control in the faba bean.

Environment × genotype interaction significantly affects seed characteristics in faba beans.Only FB_227 and FB_231 showed stable performance across locations with high values for seed characteristics.Environment × genotype interaction hindered the detection of stable markers for seed characteristics using GWAS.

Environment × genotype interaction significantly affects seed characteristics in faba beans.

Only FB_227 and FB_231 showed stable performance across locations with high values for seed characteristics.

Environment × genotype interaction hindered the detection of stable markers for seed characteristics using GWAS.

This study investigated how different faba bean genotypes grow and perform in different environments. We found that the environment plays an important role in how yield‐related traits like seed size and shape appear. To address this, we used a selection index, a method that combines all seed traits, to help identify the best‐performing genotypes across regions. Using this approach, we identified two promising faba bean lines, FB_227 and FB_231, that could be valuable for future breeding programs aimed at improving seed traits. We also discovered several new genetic markers linked to important seed traits. Some of these markers affect multiple seed traits at the same time, making them especially useful for marker‐assisted selection